Package org.codehaus.loom.components.classloader

Source Code of org.codehaus.loom.components.classloader.DefaultClassLoaderManager

/* ====================================================================
* Loom Software License, version 1.1
*
* Copyright (c) 2003, Loom Group. All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in
*    the documentation and/or other materials provided with the
*    distribution.
*
* 3. Neither the name of the Loom Group nor the name "Loom" nor
*    the names of its contributors may be used to endorse or promote
*    products derived from this software without specific prior
*    written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ====================================================================
*
* Loom includes code from the Apache Software Foundation
*
* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 1997-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in
*    the documentation and/or other materials provided with the
*    distribution.
*
* 3. The end-user documentation included with the redistribution,
*    if any, must include the following acknowledgment:
*    "This product includes software developed by the
*    Apache Software Foundation (http://www.apache.org/)."
*    Alternately, this acknowledgment may appear in the software
*    itself, if and wherever such third-party acknowledgments
*    normally appear.
*
* 4. The names "Jakarta", "Avalon", and "Apache Software Foundation"
*    must not be used to endorse or promote products derived from this
*    software without prior written permission. For written
*    permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
*    nor may "Apache" appear in their name, without prior written
*    permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
package org.codehaus.loom.components.classloader;

import java.io.File;
import java.net.URL;
import java.security.Policy;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.codehaus.loom.classman.builder.LoaderBuilder;
import org.codehaus.loom.classman.builder.LoaderResolver;
import org.codehaus.loom.classman.metadata.ClassLoaderMetaData;
import org.codehaus.loom.classman.metadata.ClassLoaderSetMetaData;
import org.codehaus.loom.classman.metadata.FileSetMetaData;
import org.codehaus.loom.classman.metadata.JoinMetaData;
import org.codehaus.loom.classman.reader.ClassLoaderSetReader;
import org.codehaus.loom.classman.verifier.ClassLoaderVerifier;
import org.codehaus.loom.components.extensions.pkgmgr.ExtensionManager;
import org.codehaus.loom.components.extensions.pkgmgr.PackageManager;
import org.codehaus.loom.extension.Extension;
import org.codehaus.loom.interfaces.ClassLoaderManager;
import org.codehaus.loom.interfaces.ClassLoaderSet;
import org.codehaus.loom.xmlpolicy.builder.PolicyBuilder;
import org.codehaus.loom.xmlpolicy.metadata.PolicyMetaData;
import org.codehaus.loom.xmlpolicy.reader.PolicyReader;
import org.codehaus.spice.configkit.PropertyExpander;
import org.codehaus.dna.AbstractLogEnabled;
import org.codehaus.dna.Active;
import org.codehaus.dna.Composable;
import org.codehaus.dna.Configuration;
import org.codehaus.dna.ConfigurationException;
import org.codehaus.dna.MissingResourceException;
import org.codehaus.dna.ResourceLocator;
import org.codehaus.dna.impl.ConfigurationUtil;
import org.w3c.dom.Element;

/**
* Component that creates and manages the {@link ClassLoader} for an application
* loaded out of a <tt>.sar</tt> deployment.
*
* <p>Currently it creates a policy based on the policy declaration in the
* configuration. It then just creates a URLClassLoader and populates it with
* the specified codebase {@link URL}s.</p>
*
* <p>In the future this class will scan the manifests for "Optional Packages"
* formely called "Extensions" which it will add to the {@link ClassLoader}</p>
*
* @author Peter Donald
* @see ClassLoaderManager
*/
public class DefaultClassLoaderManager
    extends AbstractLogEnabled
    implements ClassLoaderManager, Composable, Active
{
    /**
     * Constant for name of element that indicates custom classloader tree to
     * define.
     */
    private static final String CLASSLOADERS_ELEMENT = "classloaders";

    /**
     * Component to manage "Optional Packages" aka Extensions to allow programs
     * to declare dependencies on such extensions.
     */
    private PackageManager m_packageManager;

    /**
     * Parent ClassLoader for all applications aka as the "common" classloader.
     */
    private ClassLoader m_commonClassLoader;

    /**
     * The utility class used to verify {@link ClassLoaderMetaData} objects.
     */
    private final ClassLoaderVerifier m_verifier = new ClassLoaderVerifier();

    /**
     * Utility class to build map of {@link ClassLoader} objects.
     */
    private final LoaderBuilder m_builder = new LoaderBuilder();

    /**
     * Utility class to read {@link ClassLoaderSetMetaData} objects from XML
     * trees.
     */
    private final ClassLoaderSetReader m_reader = new ClassLoaderSetReader();

    /**
     * The map of predefined ClassLoaders. In the current incarnation this only
     * contains the system classloader.
     */
    private Map m_predefinedLoaders;

    /**
     * The contextdata used in interpolation of the policy configuration file.
     */
    private final Map m_data = new HashMap();

    /**
     * The property expander that will expand properties in the policy
     * configuraiton file.
     */
    private final PropertyExpander m_expander = new PropertyExpander();

    /**
     * @dna.dependency type="ExtensionManager"
     * @dna.dependency type="ClassLoader/common"
     */
    public void compose( final ResourceLocator locator )
        throws MissingResourceException
    {
        final ExtensionManager extensionManager = (ExtensionManager) locator.lookup(
            ExtensionManager.class.getName() );
        m_packageManager = new PackageManager( extensionManager );
        m_commonClassLoader = (ClassLoader) locator.lookup(
            ClassLoader.class.getName() + "/common" );
    }

    /**
     * Setup the map of predefined classloaders.
     *
     * @throws Exception if unable to setup map
     */
    public void initialize() throws Exception
    {
        m_data.putAll( System.getProperties() );

        final Map defined = new HashMap();
        defined.put( "*system*", ClassLoader.getSystemClassLoader() );
        defined.put( "*common*", m_commonClassLoader );
        defined.put( "*shared*", m_commonClassLoader );
        m_predefinedLoaders = Collections.unmodifiableMap( defined );
    }

    public void dispose() throws Exception
    {
    }

    /**
     * Create a {@link ClassLoader} for a specific application. See Class
     * Javadoc for description of technique for creating {@link ClassLoader}.
     *
     * @param environment   the configuration "environment.xml" for the
     *                      application
     * @param homeDirectory the base directory of application
     * @param workDirectory the work directory of application
     * @return the ClassLoader created
     * @throws Exception if an error occurs
     */
    public ClassLoaderSet createClassLoaderSet(
        final Configuration environment,
        final Map data,
        final File homeDirectory,
        final File workDirectory ) throws Exception
    {
        //Configure policy
        final Configuration policyConfig = environment.getChild( "policy" );
        final Policy policy = configurePolicy( policyConfig,
                                               data,
                                               homeDirectory,
                                               workDirectory );

        final ClassLoaderSetMetaData metaData = getLoaderMetaData( environment );

        m_verifier.verifyClassLoaderSet( metaData );

        final LoaderResolver resolver = new SarLoaderResolver(
            m_packageManager, policy, homeDirectory, workDirectory );
        setupLogger( resolver );
        final Map map = m_builder.buildClassLoaders( metaData,
                                                     resolver,
                                                     m_predefinedLoaders );
        final ClassLoader defaultClassLoader = (ClassLoader) map.get(
            metaData.getDefault() );
        return new ClassLoaderSet( defaultClassLoader, map );
    }

    /**
     * Extract the {@link ClassLoaderMetaData} from the environment
     * configuration. If no &lt;classloader/&gt; section is defined in the
     * config file then a default metadata will be created.
     *
     * @param environment the environment configuration
     * @return the {@link ClassLoaderMetaData} object
     */
    private ClassLoaderSetMetaData getLoaderMetaData(
        final Configuration environment ) throws Exception
    {
        final boolean loaderDefined = isClassLoaderDefined( environment );
        if( !loaderDefined )
        {
            return createDefaultLoaderMetaData();
        }
        else
        {
            final Configuration loaderConfig = environment.getChild(
                CLASSLOADERS_ELEMENT );
            final Element element = ConfigurationUtil.toElement( loaderConfig );
            return m_reader.build( element );
        }
    }

    /**
     * Create the default {@link ClassLoaderSetMetaData}. The default metadata
     * includes all jars in the /SAR-INF/lib/ directory in addition to the
     * /SAR-INF/classes/ directory.
     *
     * @return the default {@link ClassLoaderSetMetaData} object
     */
    private ClassLoaderSetMetaData createDefaultLoaderMetaData()
    {
        final String[] includes = new String[]{"SAR-INF/lib/*.jar"};
        final String[] excludes = new String[ 0 ];
        final FileSetMetaData fileSet = new FileSetMetaData( ".",
                                                             includes,
                                                             excludes );
        final String name = "default";
        final String parent = "*system*";
        final String[] entrys = new String[]{"SAR-INF/classes/"};
        final Extension[] extensions = new Extension[ 0 ];
        final FileSetMetaData[] filesets = new FileSetMetaData[]{fileSet};
        final ClassLoaderMetaData loader = new ClassLoaderMetaData( name,
                                                                    parent,
                                                                    entrys,
                                                                    extensions,
                                                                    filesets );
        final String[] predefined = new String[]{parent};
        final ClassLoaderMetaData[] classLoaders = new ClassLoaderMetaData[]{
            loader};
        final JoinMetaData[] joins = new JoinMetaData[ 0 ];
        return new ClassLoaderSetMetaData( name,
                                           predefined,
                                           classLoaders,
                                           joins );
    }

    /**
     * Return true if environment config defines "classloader" element, false
     * otherwise.
     *
     * @param environment the environment config
     * @return true if environment config defines "classloader" element, false
     *         otherwise.
     */
    private boolean isClassLoaderDefined( final Configuration environment )
    {
        return null != environment.getChild( CLASSLOADERS_ELEMENT, false );
    }

    /**
     * Setup policy based on configuration data.
     *
     * @param configuration the configuration data
     * @param data          the context data used to expand policy file
     * @param baseDirectory the applications base directory
     * @throws ConfigurationException if an error occurs
     */
    private Policy configurePolicy( final Configuration configuration,
                                    final Map data,
                                    final File baseDirectory,
                                    final File workDirectory )
        throws Exception
    {
        final SarPolicyResolver resolver = new SarPolicyResolver(
            baseDirectory, workDirectory );
        setupLogger( resolver );
        final PolicyBuilder builder = new PolicyBuilder();
        final PolicyReader reader = new PolicyReader();
        final SarPolicyVerifier verifier = new SarPolicyVerifier();
        setupLogger( verifier );

        final Element element = ConfigurationUtil.toElement( configuration );
        final HashMap newData = new HashMap();
        newData.putAll( m_data );
        newData.putAll( data );
        newData.put( "/", File.separator );

        m_expander.expandValues( element, newData );

        element.setAttribute( "version", "1.0" );
        try
        {
            final PolicyMetaData policy = reader.readPolicy( element );
            verifier.verifyPolicy( policy );
            return builder.buildPolicy( policy, resolver );
        }
        catch( final Exception e )
        {
            throw new ConfigurationException( e.getMessage(), e );
        }
    }
}
TOP

Related Classes of org.codehaus.loom.components.classloader.DefaultClassLoaderManager

TOP
Copyright © 2018 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.